In conventional (scanline-based) ultrasonic imaging, a focused beam of ultrasound energy (a scanline) is transmitted into body tissues to be examined and echoes returning along the same scanline are detected and plotted. A complete image may be formed by combining multiple scanlines. While ultrasound has been used extensively for diagnostic purposes, conventional scanline-based ultrasound has been greatly limited by depth of scanning, speckle noise, poor lateral resolution, obscured tissues and other problems.
Significant improvements have been made in the field of ultrasound imaging with the creation of multiple aperture imaging, some examples of which are shown and described in U.S. Pat. No. 8,007,439 titled “Method and Apparatus to Produce Ultrasonic images Using Multiple Apertures,” U.S. patent application Ser. No. 13/029,907, filed Feb. 18, 2010, titled ″Point Source Transmission and Speed-Of-Sound Correction Using Multiple-Aperture Ultrasound Imaging, U.S. patent application Ser. No. 12/760,375, filed Apr. 4, 2010, titled “Universal Multiple Aperture Medical Ultrasound Probe,” and U.S. patent application Ser. No. 12/760,327, titled “Multiple Aperture Ultrasound Array Alignment Fixture,” all of which are incorporated herein by reference. Multiple aperture imaging methods and systems allow for ultrasound signals to be both transmitted and received from separate apertures.
Ultrasound probes constructed to perform multiple aperture ultrasound imaging typically contain multiple separate transducer arrays. During construction of such a probe, the multiple arrays need to be aligned in a common imaging plane and in a desired orientation relative to one another. Some methods of performing such alignment and construction are shown and described in U.S. patent appliation Ser. No. 12/760,327. Room for further improvement remains.